Morphologic studies were made of various features of the congestive cardiomyopathy induced in White Pekin ducklings by the administration of furazolidone. These studies show that a dose of 750 mg of furazolidone per kg of feed for 4 weeks is necessary to induce cardiomyopathy in a consistent and reproducible manner, and that this cardiomyopathy is characterized by marked cardiac dilatation and myocytolysis.